Glossary
- Axis (axial) - central lobe running the length of
the trilobite body
- Cephalon (cephalic) - frontmost part of the trilobite;
ie. the head
- Ecdysis - shedding of the exoskeleton
- Enrollment - bending and rolling up of the body to
enclose vunerable organs on the trilobites underside
- Furrow - linear groove, often defines adjacent convex
features such as the lobes of the glabella
- Gena - cephalic shell of the cephalon surrounding
the glabella, usually divided by sutures
- Genal angle - angle formed by the meeting of the side
and rear margins of the cephalon
- Genal Spine - a spine anywhere on the gena of the
cephalon
- Glabella - middle part of the cephalon, usually convex
and lobed
- Gonatoparian - facial sutures ending at the tip of
the genal angle
- Holochroal - eyes with compound lenses all directly
in contact, covered by a single, smooth continuous corneal surface
- Hypostome (hypostomal) - a piece of exoskeleton on
the underside of the cephalon, thought ot be a mouthpart
- Pleura (pl. Pleurae)(pleural) - side part of the thoracic
segment or non axial part of the pygidium
- Proparian - facial sutures ending forward of the genal
angle
- Pygidium (pygidial) - hindmost section of the trilobite
composed of fused segments, its separated from the thorax by
an articulation
- Rostral Plate - middle portion of the anteriormost
edge of the cephalon, typically where the hypostome attaches
- Schizochroal - eyes with compound lenses, each with
a separate cornea, separated from each other by deep scleral
walls with the membrane extending downwards into the sclera
- Spinose - bearing spine or spines
- Suture - linear break in the exoskeleton, typically
along which parts separate during molting
- Thorax (thoracic) - middle, segmented body portion
between the cephalon and the pygidium
- Tuberculate - bearing tubercules or simmilar sculpturing
on the outer exoskeleton
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Author: Sarah Vinnell
Last updated: 21/11/05
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